The present invention generally relates to an integrating distance meter for a vehicle, and more particularly to an integrating distance meter for a vehicle including an odometer counter having a plurality of numeral wheels rotatably juxtaposed to a frame and adapted to integrate and display the distance traveled by the vehicle in an unresettable manner, and a trip counter having a plurality of numeral wheels rotatably juxtaposed to a frame and adapted to integrate and display the distance traveled by the vehicle in a resettable manner. Furthermore, the present invention relates to a combination instrument for a vehicle, and more particularly to a combination instrument for a vehicle which combines an integrating distance meter having a plurality of numeral wheels rotatably juxtaposed to a frame and adapted to display the distance travel by the vehicle, and the analog counter for indicating a measured vehicle speed or the like by means of a pointer driven by an electrically-operated movement such as a cross-coil-type movement and the scale of a dial secured to a frame of the integrating distance meter.
In general, a vehicle instrument such as the one illustrated in a front elevational view in FIG. 6 is mounted in a vehicle. In the drawing, window holes 2a and 2b are respectively formed in a dial 2 of a speedometer for displaying vehicle speed in cooperation with a pointer 1, one above and the other below the pointer 1 as viewed in FIG. 6, and the distance traveled by the vehicle is integrated by an odometer counter in an unresettable manner and is displayed through the window hole 2a, while the distance traveled by the vehicle is integrated by a trip counter in a resettable manner and is displayed through the window hole 2b. The reference numeral 3 denotes a reset button for resetting the display of the distance on the trip counter.
As an integrating distance meter disposed in the rear of the dial, shown in FIG. 6, for displaying an integrated distance, one having an arrangement illustrated in a top view in FIG. 7, a side elevational view in FIG. 8, and a cross-sectional view in FIG. 9 has been used.
As shown in the drawings, the integrating distance meter for a vehicle is arranged such that two support shafts 21a and 22a are supported on a single frame 10 parallel with each other at a predetermined interval corresponding to the distance between the window holes 2a and 2b of the dial 2, and numeral wheels 21b of an odometer counter 21 are rotatably juxtaposed to one support shaft 21a, while numeral wheels 22b of a trip counter 22 are rotatably juxtaposed to the other support shaft 22a. In addition, a stepping motor 23 for driving both the numeral wheels 21b and 22a is assembled and secured to the same frame 10.
In the integrating distance meter arranged as described above, the stepping motor 23 is electrically connected to a hard printed circuit board (HPC) 24 having thereon various electronic components constituting an electrical circuit for generating a drive signal for driving the stepping motor 23. As the stepping motor 23 is driven in correspondence with the travelling of the vehicle, the odometer counter 21 and the trip counter 22 are operated so as to integrate and display the distance traveled by the vehicle.
The reference numeral 25 denotes a cross-coil-type movement having a rotating shaft 25a at a distal end of which the pointer 1 is fixed, the movement 25 being adapted to drive the pointer 1 and display the speed. This movement 25 is accommodated and fixed in a space formed in the frame 10 below the numeral wheels 21b and 22b.
FIG. 9 shows a cross-sectional view of such a combination indication instrument. FIG. 9 is a cross-sectional view taken along line A--A in FIG. 6.
In the drawing, the cross-coil-type movement 25 for driving the pointer of the speedometer in correspondence with a measured amount, as well as the odometer counter 21 and the trip counter 22 which constitute an integrating distance meter 20, are disposed below the dial 1.
The cross-coil-type movement 25 has a coil bobbin 101, a pair of coils 102 wound around the outer periphery of the coil bobbin 101 perpendicularly to each other, and a magnet rotor 104 accommodated rotatably in a cavity 103 formed in the coil bobbin 101, and the rotating shaft 105 of the magnet rotor 104 has one end projecting out of the coil bobbin 101. By virtue of this arrangement, electric current corresponding to the measured amount is allowed to flow across the pair of coils 102 so as to respectively generate magnetic fields perpendicular to each other. As a result, the magnet rotor 104 and its rotating shaft 25a are rotated in such a manner that the direction of a synthetic magnetic field obtained by synthesizing the perpendicular magnetic fields and the direction of the N, S poles of the magnet rotor 104 will agree with each other.
Meanwhile, the odometer counter 21 and the trip counter 22 are arranged such that the numeral wheels 21b and 22b are respectively fitted rotatably on the support shafts 21a and 22a supported on the common frame 10, and an upper-digit numeral wheel is driven a one-tenth revolution by one revolution of a lower-digit numeral wheel to effect carrying. The dial 1 is secured to the coon frame 10 by means of screws or the like with the dial 1 superposed on a light-transmitting plate 30.
The movement 25 arranged as described above is secured, by means of set screws serving as terminals, to the HPC 24 on which are mounted electrical components such as ICs and resistors constituting a circuit for generating a signal for causing electric current corresponding to a measured amount to flow across the pair of coils 102. As the HPC 24 to which the movement 10 is thus fixed is secured to the frame 10 by means of screws 32 or the like, the movement 25 is accommodated and fixed in a cavity 202 formed between the odometer counter 21 and the trip counter 22, thereby forming the movement 25 and the integrating distance meter 20 integrally with each other.
The rotating shaft 25a of the movement 25 fixed to the common frame 10 via the HPC 24 as described above projects through the obverse surface of the dial 2 vie holes 201a, 30a, and 2d which are respectively formed in the frame 10, the light-transmitting plate 30, and the dial 2. The pointer 1 is secured to this projecting end by pressure fitting. In addition, the numeral wheels 21b of the odometer counter 21 and the numeral wheels 22b of the trip counter 22 face the window holes 2a and 2b of the dial 2.
With the above-described conventional integrating distance meter, various problems have been encountered since the odometer counter 21 and the trip counter 22 are assembled to the single frame 10.
For instance, there are numerous kinds of trip counter 22 whose number of digits and design differ depending on the type of vehicle and the grade. For this reason, integrating distance meters for vehicles in which various trip counters 22 are selectively combined with one kind of odometer counter 21 are required.
In such a case, with the above-described conventional 111, before the specifications of the trip counter 22 are determined, it is possible to fabricate in advance a multiplicity of odometer counters 21 without the trip counter 22 assembled thereto; however, it is necessary to store unfinished integrating distance meters each having a large frame 10, which is disadvantageous in terms of space in the light of management. In addition, there is a drawback in that, at the time when components constituting a trip counter 22 which meets required specifications are fitted to the frame 10, a large unfinished product must be handled, so that the efficiency in assembling operation is aggravated.
In addition, integrating distance meters each provided with the odometer counter 21 alone are required in some cases. In such cases, however, it is necessary to newly design and manufacture special integrating distance meters, and the number of kinds of products manufactured increases, which is disadvantageous in terms of cost and management.
As described above, the movement 25 and the integrating distance meter 20 are conventionally formed integrally by fixing the HPC 24, to which the cross-coil-type movement 25 is secured, to the frame 10 common to the odometer counter 21 and the trip counter 22 which constitute the integrating distance meter.
For this reason, if variations occur both in the fixing of the movement 25 to the HPC 25 and in the fixing of the HPC 25 to the common frame 10, and if the variations overlap in such a manner as to be added together, the positioning of the movement 25 with respect to the common frame 10 becomes substantially inaccurate, so that the rotating shaft 25a of the movement 25 fails to be located at the center of a hole 1d bored in the dial 2.
If this occurs, there is problem in that the pointer 1 secured to the tip of the rotating shaft 25a becomes offset from its predetermined position on the dial, with the result that the relationship between the pointer 1 and the window holes 2a and 2b and the relationship between the pointer 1 and a scale 1a become inaccurate.
In addition, with the above-described conventional combination instrument, since an assembling method is adopted in which the HPC 24 formed integrally with the movement 25 is assembled to the already assembled integrating distance meter 20, it is necessary to handle the HPC 24 formed integrally with the movement 25. Hence, such an arrangement has not been favorable in effecting automatic assembly.